$('.CommentTabs ul').append('<li><a href="#" class="image_insert_form">Insert Image</a></li>');

$('a.image_insert_form').live('click', function() {
    var image_url = prompt("Insert Image", "Type your image url here");
	if (image_url!=null && image_url!="") {
		$('textarea#Form_Body').val($('textarea#Form_Body').val()+'<img src="'+image_url+'" alt="" />');
	}
	return false;
});